Once you have loaded the file into Wondershare Video Converter Ultimate, the following steps will explain how to trim the video.
1. Click on the Edit button 
on the right side of the files thumbail.
2. Click on the Trim tab in the window that opens.
3. Click on the Add trim marker to add a pair of sliders to determine where to trim the video. Once you have the sliders, drag them to select the section of the video you want to trim. Make sure that you set if you want to keep or discard the selected region under the preferences. Alternatively it is possible to manually set the Start Time and End Time for your selection.
4. Wondershare Video Converter Ultimate supports trimming multiple sections, allowing you to trim several parts from your video at one time. To do this, drag the Play slider to the new location and click on Add trim marker to add more trim sliders. Use the instructions above to define the new section to be trimmed. If you decide that you don’t need the extra sliders, click on Reset to remove them.
This link offers a video guide to assist: http://youtu.be/RlkLN1KsVfg
Tips:
1. There are two options in the Preference drop down list; Keep the selected section or Delete the selected section. Set this according to how you want to work with the video.
2. After you have completed trimming your video, click OK to exit the window. Once you convert the video it will save with the settings you have specified.